Safe needle, placebo needle, and needle set for double-blinding

ABSTRACT

A safety needle and a placebo needle are provided for a double blind test. The placebo needle comprises a guide tube; a first stuffing in the guide tube to give resistance to a needle body during its passage therethrough; and a second stuffing in the guide tube at a lower position, to give resistance to the needle body during passage through the guide tube to a specified depth. The needle body is movably held by the first stuffing, and has a length sufficiently long to allow its point to stop just on or above the skin surface. A stopper is mounted to a needle handle or to the guide tube, and prevents the needle handle from advancing further.

TECHNICAL FIELD

The present invention relates to a needle set which can be profitablyused for double-blind test for strictly evaluating the therapeuticeffect of acupuncture in which it is masked from both of the subject andthe practitioner whether a true needle or a placebo needle is used, howdeep the needle is inserted, what is the diameter of the needle, andwhere the needle is inserted (acupoint or non-acupoint). This inventionfurther relates to a safety needle and placebo needle suitably used as amember of the double-blind needle set. This invention further relates toa safety needle which does not cause any infection in the patient, thepractitioner, and the disposer for used needles.

BACKGROUND ART

It is said that the most excellent and practical method among themethods for evaluating the therapeutic effect of acupuncture is asingle-blind method in which only the subject is blinded. In theexperiment based on the single-blind method, the control group receivesplacebo stimulation resembling a needle insertion on an acupoint whilethe experimental group receives stimulation with true needle insertionat the same acupoint; the results from the two groups are compared; andthe therapeutic effect is evaluated.

The currently proposed methods for giving placebo stimulation includesthe following three:

(1) To place a guide tube instead of a needle on a site of the skin, andtap the top end of the guide tube;

(2) To transform the tip of a needle into impenetrable to the skin,place the transformed tip on a site of the skin, and press the upper endof the needle (see, for example, The Lancet, vol. 352, Aug. 1998, pp.364-365); and

(3) To place an electrode for percutaneous electrical stimulation on asite of the skin.

Methods (1), (2) and (3) are all employed in experiments based on thesingle-blind method. With methods (1) and (2), it is possible tocompletely make the subject unaware of whether the stimulation appliedis by a true needle inserted or by a placebo needle pressed, as long asthe experiment is properly conducted. This was indeed confirmed formethod (2) (see, for example, The Lancet, vol. 352, Aug. 1, 1998, pp.364-365). However, with method (3), it is hardly possible to mask thenature of stimulation from the subject, because the shape of device usedfor stimulation, sensation the subject felt induced by a stimulation,etc. are clearly different from those of true needle insertion.

However, with all the above methods aimed at giving placebo stimulation,it is impossible to make the practitioner unaware of the nature ofstimulation, that is, the methods can not mask the practitioner whetherhe applied a true needle or a placebo needle. Namely, all the abovemethods are inadequate to serve as a placebo stimulation to be given toa control group. When the practitioner applies a needle to a subject,the practitioner feels, through his fingers and hands, the needle makinga puncture on the skin, penetrating the skin, and advancing deep intothe human body, or he is aware of the point at needling before needleapplication. Thus, it has been thought impossible to mask the nature ofstimulation from the practitioner. Under such current situations, theConsensus Development Conference of US National Health Institute (NIH)concludes that, for the evaluation of acupuncture, it can not helpadopting single-blind test because in acupuncture study it is possibleto mask the nature of stimulation only from the subject (The Lancet,vol. 352, Sep. 19, 1998, p. 992).

However, because, with single-blind test, expectation or zeal of thepractitioner during therapy is transmitted to the subject, a demand ismanifest for double-blind method which can mask the nature ofstimulation from the practitioner as well as from the subject, toscrutinize the effect of acupuncture.

The acupuncture therapy currently widely in use is based on theinsertion technique using the guide tube. The therapy based on theinsertion technique is executed with a needle and the guide tubeseparately prepared. The practitioner inserts the needle into a guidetube by one hand, and forms Oshide(the hand by which to hold the guidetube or the needle during the needle insertion or the needle removal) byplacing the thumb and the index finger of the other hand being lightlyin contact with each other on a site of the skin; and inserts the guidetube contained the needle between the pads of the thumb and the indexfinger of Oshide and holds the guide tube adjusting a needle insertionangle being preferable; and taps the top end of the needle handle withthe pad of the index finger of Sashide(or the hand by which to insert orremove the needle) to open thereby a puncture on the skin(usually, theguide tube used for the insertion therapy has the length shorter byabout 3-4 mm than the total length of the needle, and thus the needle isinserted by that difference into the human body by tapping with the padof the index finger). After the puncture is opened, the guide tube aloneis removed to leave the partly sticking needle on the site; the Oshidedirectly holds the needle body, and inserts it into the human body withthe holding needle. When the needle reaches to a desired depth, theOshide keeps holding the needle body, or leaves the needle to standthere for an arbitrary period (in-situ needle). Then, the Oshide isformed around the needle to extract it from the body. Immediately afterremoval, the used needle including its needle body and its tip is bare.

As seen above, during the insertion therapy with a guide tube, the guidetube and the needle body are separated. Thus, the Oshide directlycontacts with the needle body when the practitioner inserts or removesthe needle into or from the body. Accordingly, before insertion, theneedle body may be contaminated through contact with the fingers andhands of the practitioner. Because, for removal, the needle uncoveredwith the guide tube is extracted from the patient's body, thepractitioner's fingers and hands may be contaminated with the patient'sbody fluid through contact with the bare needle body and tip of theneedle. The same risk persists even when the practitioner wears glovesduring therapy.

The practitioner or the disposer who handles acupuncture needles maydamage himself by accidental contact with a used needle with its bareneedle body and its tip. Currently, at acupuncturist training schoolsand clinical centers used needles are disposed into a cylindrical trashcase having a bottom diameter of 8 cm and a height of 17 cm. If the casebecomes full, used needles are removed by hand and put into a cardboardbox for medical waste. During disposal, when the practitioner put awayused needles into a trash case, or when disposer transfers used needlesfrom the trash case to a cardboard box, he may damage himself byaccident. Indeed, there was reported such a case.

To prevent contamination in acupuncture therapy, a method is proposed inwhich the practitioner wears finger covers or operation gloves duringtherapy. However, this method poses a number of problems: wearing coversor gloves is a nuisance to the practitioner, and the practitioner'sfingers and hands may contact with the contaminated surfaces of coversand gloves.

A variety of means to prevent infection during therapy, or duringdisposal of used needles have been proposed.

Recently, covering the needle body with a coat (Japanese PatentLaid-Open No. Sho 57-131446) and covering the lowest end of a needlewith a tube sufficiently small to enter through the inner space of aguide tube (Japanese Patent Laid-Open No. Sho 57-177752) are proposed.With these methods, a needle body and a guide tube are separated fromeach other during therapy, and they are separately disposed of aftertherapy. Namely, when disposed of, both the needle body and its tip arebare, and thus these methods do not take into account the risk of athird person who may be exposed, after therapy, to contamination bytouching such a needle body or a guide tube accidentally.

The first object of this invention is to provide a safety needle and aplacebo needle ensuring the introduction of a double-blind methodwhereby it is possible to make both the practitioner and the subjectunaware of whether the needle applied is a true needle or a placeboneedle, or whether the insertion point corresponds with an acupoint ornot, thereby enabling a strict evaluation of the effect of acupuncturetherapy.

Another object of this invention is to provide a safety needle free fromthe risk of infection, with which infection from the patient to thepractitioner, and from the practitioner to a third person, and toprovide a safety needle free from the risk of exposure to infection ofthe disposer who might otherwise contaminate himself by damaging himselfby accident with the needle when disposing.

A further object of this invention is to provide a needle set fordouble-blind test with which it is possible to mask the depth of needleinsertion, and the diameter of needle body.

DISCLOSURE OF THE INVENTION

The safety needle of the present invention to achieve the above object,particularly the safety needle of the present invention to beincorporated into a needle set for double-blind test comprises: (1) aguide tube; (2) one or more stuffings holding needle body which areplugged into the guide tube to be fixed at a desired position, to giveresistance to a needle body during its passage therethrough, and to holdthe needle body; (3) the needle body movably held by the stuffing whichhas the length longer than that of the guide tube by an amount equal tothe insertion depth of the needle body; and (4) a stopper which ismounted to the lower end of a needle handle attached to the top of theneedle body, or which is mounted to the top end of the guide tube, andprevents the needle handle from advancing further at the moment when theneedle point reach a specified insertion depth; (5) wherein the guidetube is longer than the insertion depth of the needle body.

The placebo needle of the present invention to achieve the above object,or the placebo needle of the present invention to be incorporated into aneedle set for double-blind test comprises: (1) a guide tube; (2) one ormore first stuffings which are plugged into the guide tube to be fixedat a desired position, to give resistance to a needle body during itspassage therethrough, and to hold the needle body; (3) one or moresecond stuffings which are plugged into lower position of the guide tubeand fixed, to give similar sensation to the skin puncture and the tissuepenetration during passage of the needle body therethrough to reach aspecified depth; (4) the needle body movably held by the first stuffingwhich has the length sufficiently long to allow its point to stop juston/above the skin surface when the needle body is advanced through thecavity of the guide tube as far as possible; and (5) a stopper which ismounted to the lower end of the handle needle attached to the top of theneedle body, or which is mounted to the upper end of the guide tube, andprevents the needle handle from advancing further into the guide tubewhen the point of the needle body reaches just on/above the skinsurface.

Another placebo needle of the present invention comprises: (1) a guidetube; (2) one or more stuffings holding needle body which are pluggedinto the guide tube to be fixed at a desired position, to giveresistance to the needle body during its passage therethrough; (3) theneedle body movably held by the stuffing holding needle body which hasthe length sufficiently long to allow its point to stop just on/abovethe skin surface when the needle body being advanced through the cavityof the guide tube as far as possible; and (4) a stopper which is mountedto the lower end of a needle handle attached to the top of the needlebody, or which is mounted to the top end of the guide tube, and preventsthe needle handle from advancing further into the guide tube when thepoint of the needle body being advanced through the cavity of the guidetube reaches just on/above the skin.

It is possible to combine the safety needle and the placebo needle intoa needle set suitably used for double-blind test.

The needle set of this invention for double-blind test incorporating aplacebo needle with the second stuffing, is characterized by that, forthe safety needle and placebo needle, the guide tubes are the same inlength, the portions of the needles bodies protruding from the top endof the guide tubes are the same in length, the needle handles are thesame in length, and the distance from the lowest end of the needle bodyof the safety needle to the skin surface is the same as the distancefrom the lowest end of the needle body of the placebo needle to theupper surface of the second stuffing; the upper surface of the secondstuffing is placed at a level higher than the bottom end of the guidetube by an amount equal to the insertion depth of the safety needle; andthe two needles can not be distinguished from their appearances. It isnecessary for blinding both the practitioner and the subject regardingwhether a real needle or a placebo needle applied to make the safetyneedle and the placebo needle look so similar that they can not bedistinguished from their appearances. For this purpose, the guide tubeshould be preferably opaque.

The needle set of this invention for double-blind test incorporating aplacebo needle with no second stuffing is characterized by that: for thesafety needle and placebo needle, the guide tubes are the same inlength, the portions of the needles bodies protruding from the top endof the guide tube are the same in length, and the needle handles are thesame in length; and the two needles can not be distinguished from theirappearances. It is necessary for blinding both the practitioner and thesubject regarding whether a real needle or a placebo needle applied tomake the safety needle and the placebo needle look so similar that theycan not be distinguished from their appearances. The stuffing forplacebo needle having a property as described above is preferably madeof a material which has resistance to cancel resistance the practitionerwould feel when he inserts a needle into the skin, and advances itthrough the skin. The needle set incorporating such a placebo needle fordouble-blind test may be suitable for an acupuncturist unaccustomed withthe technique as well as for a practitioner without acupuncture license,or may be suitable for in a case where shallow insertion of a safetyneedle is needed, the patient has a thin and soft skin, or the siteapplied has a soft subcutaneous tissue.

Another needle set of this invention for double-blind test comprises:(1) a group of safety needles selected according to the specifieddouble-blind test from needles which are different in at least one ofthe following properties, the material, length, color and shape of theneedle handle; the material, total length, the diameter of the needlebody; length of the protruding portion of the needle body from the upperend of the guide tube; the distance from the lowest end of the needlebody to the skin surface; the insertion depth of the needle body; thematerial, length, color and shape of the guide tube; and the material,quantity, the number and position of the stuffing, (2) a group ofplacebo needles selected from needles which are different in at leastone of the following properties, the material, length, color and shapeof the needle handle; the material, total length, the diameter, lengthof the protruding portion of the needle body from the upper end of theguide tube; distance from the lowest end of the needle body to the uppersurface of the second stuffing; the material, length, color and shape ofthe guide tube; and the material, quantity, the number and the positionof the first stuffing; and the material, the quantity, the number andthe position of the second stuffing; and (3) a set for double-blind testconsisting of the safety needle group and the placebo needle group.

With the needle set for double-blind test, it is possible to choosearbitrarily appropriate combination for the modality or an appropriatenumerical combination of safety and placebo needles from the viewpointof the above each character according to the specified double-blindtest.

The length of the guide tube is defined as the length of the guide tubeincluding the thickness of stopper if the guide tube has a stopperprotruding from its top end.

The length of a needle body should be determined by measuring from thelowest end of a stopper to the point, if the needle handle has thestopper at its lowest end, and that stopper protrudes from the lowestend of the needle handle, or if the stopper is placed along the needlebody at an arbitrary position lower than the lowest end of the needlehandle.

The guide tube of a safety needle or a placebo needle may have anadhesive or sucking pedestal on its bottom end to keep both kind ofneedle stable on the skin surface, thereby ensuring the fixation of theguide tube on the skin surface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the safety needle of the present invention before use: FIG.1(a) is a frontal view; FIG. 1(b) a top view; and FIG. 1(c) a sectionalview of the needle cut along line A-A′ in FIG. 1(b).

FIG. 2 shows how the safety needle of FIG. 1 is inserted through theskin into the human body.

FIG. 3 shows the placebo needle of the present invention before use:FIG. 3(a) is a frontal view; FIG. 3(b) a top view; and FIG. 3(c) asectional view of the needle cut along line B-B′ in FIG. 3(b).

FIG. 4 shows how the placebo needle of FIG. 3 is applied onto the humanskin surface.

FIG. 5 shows the safety needle of FIG. 1 having the pedestalintegratively united to its lowest end, which has the adhesive layer onits undersurface to firmly stick to the human skin surface: FIG. 5(a) isa frontal view; FIG. 5(b) a top view; and FIG. 5(c) a sectional view ofthe needle cut along line C-C′ in FIG. 5(b).

FIG. 6 shows how the safety needle of FIG. 5 is inserted through theskin into the human body.

FIG. 7 shows the placebo needle of FIG. 3 having the pedestalintegratively united to its lowest end, which has the adhesive layer onits undersurface to firmly stick to the human skin surface: FIG. 7(a) isa frontal view; FIG. 7(b) a top view; and FIG. 7(c) a sectional view ofthe needle cut along line D-D′ in FIG. 7(b).

FIG. 8 shows how the placebo needle of FIG. 7 is applied onto the humanskin surface.

FIG. 9 shows the safety needle of the present invention having thestopper attached to the lowest end of the needle handle: FIG. 9(a) is afrontal view; FIG. 9(b) a top view; and FIG. 9(c) a sectional view ofthe needle cut along line A-A′ in FIG. 9(b).

FIG. 10(a) shows the needle in which a portion of the stopper protrudesfrom the lowest end of handle; FIG. 10(b) another needle in which theflange-like stopper is arranged beneath the lowest end of handle; andFIG. 10(c) a still further needle in which the stopper wraps around thelowest end of handle; and FIG. 10(d) is a still further needle of whichthe needle handle has the bulged rim at its lowest end to serve as astopper.

FIG. 11 shows the stopper mounted on the upper portion of the needlebody and underneath the needle handle.

FIG. 12 shows the placebo needle of the present invention in thecondition before use which has the stopper on the lowest end side of itsneedle handle: FIG. 12(a) is a frontal view; FIG. 12(b) a top view; andFIG. 12(c) a sectional view of the needle cut along line B-B′ in FIG.12(b).

FIG. 13 shows how the safety needle is placed at an arbitrary angle tothe skin if it must be inserted obliquely through the skin into thehuman body.

FIG. 14 shows how the placebo needle is placed at an arbitrary angle tothe skin if it must be pressed obliquely on the skin.

FIG. 15 shows the guide tube of the safety needle which has the stuffingon its top end, the stuffing protruding from the top end of the guidetube and also serving as a stopper. This stuffing is applicable to theplacebo needle as well.

FIG. 16 shows the guide tube of a safety needle, which has the stopperoutside, the stopper movably holding the needle body to allow the needleto pass along the central axis, and to give resistance to the needlebody approximately the same as that of the stuffing during passage ofthe needle body through the stuffing, and thus the stopper also servingas the stuffing. This guide tube is also applicable to the placeboneedle.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The best modes for carrying out the present invention will be explainedwith reference to attached figures.

Safety Needle

FIG. 1 shows the safety needle of the present invention before use: FIG.1(a) is a frontal view; FIG. 1(b) a top view; and FIG. 1(c) a sectionalview of the needle cut along line A-A′.

In this figure, 3 represents a guide tube; and in its upper part of theinner space is plugged and fixed a stuffing holding needle body 4 whichgives appropriate resistance to the needle body moving through thestuffing space. Namely, before use, needle body 1 of the safety needleis held stationary by the stuffing holding needle body 4.

The stuffing holding needle body 4 may be plugged and fixed at anydesired position in the guide tube 3, but should be preferably pluggedand fixed at a certain upper level. The stuffing holding needle body 4may be made of a laminated body comprising multiple layers composed ofdifferent materials. The length of the stuffing holding needle body 4and its number may be adjusted appropriately according to a given usecondition.

The stuffing holding needle body 4 placed on the top end of the guidetube 3 may have its upper surface flush with the top end of the guidetube 3 so that it can also serve as the stopper 5. Alternatively, asshown in FIG. 15, the stuffing holding needle body 4 may have its uppersurface protruding from the top end of the guide tube 3. In this case,the protruding portion of the stuffing holding needle body 4 may alsoserve as the stopper 5. The stuffing holding needle body 4 prevents theentry of the needle handle into the guide tube; and gives resistanceduring passage of the needle body through the guide tube. The stuffingholding needle body 4 also serving as the stopper will be called a“needle body holding stopper means.”

Such a needle body holding stopper means should be preferably shapedlike a film, a sheet, a plate, a bulk, a cylinder, etc., and have thediameter sufficiently small to be less than the outer diameter of theguide tube 3.

Further, for example, two kinds of stuffings holding needle body 4 maybe placed at the upper and lower portions of the internal cavity of theguide tube 3, and the one placed at the lower portion may be made ofalcohol-soaked cotton which serves as the disinfectant of the needlebody. Because the safety needle of this invention has its needle bodymovably held by the stuffing holding needle body 4 placed in theinternal cavity of the guide tube, it is possible to straightly move theneedle body during needle insertion or needle removal, and thus theguide tube also serves as Oshide.

The stuffing holding needle body 4 may be made of a cotton, a sponge,plastics, a silicone resin, a rubber, a polysaccharide, a protein, asynthetic chemical sponge, a foamed plastics, a synthetic fiber, anatural fiber, a raw meat from livestock/fish, processed meat (ham,etc.) alone or in combination. The stuffing holding needle body 4movably holds the needle body at its center, and the point 9 of needlebody 1 advances to the point apart from the lowest end of the guide tube3 by a distance S1.

The needle handle 2 is attached to the upper end of the needle body 1.The guide tube 3 has the stopper 5 on its top end to prevent the entryof the lowest end of the needle handle 2 into the guide tube 3. Thestopper 5 may be placed outside or inside of the guide tube 3. If thestopper 5 is placed outside the guide tube 3 as shown in FIG. 16, it maymovably hold the needle body in such a way as to allow the needle bodyto pass along the central axis and have a material to give resistanceduring its passage through the stopper 5, which is approximately thesame as the resistance as that by the stuffing holding needle body 4during the needle body pass through as shown in FIG. 1(c), FIG. 2, orFIG. 15. The stopper having such functions as described above will becalled a “needle body holding stopper means.” Such a needle body holdingstopper means should be preferably shaped like a film, a sheet, a plate,a bulk, a cylinder, a clip etc., and have a diameter not longer than theouter diameter of the guide tube 3. The stopper 5 may be placed at thelower end of handle 2, instead of at the side of the guide tube 3.

FIG. 9 shows the safety needle of the present invention having thestopper 25 attached to the lowest end of the needle handle 2: FIG. 9(a)is a frontal view; FIG. 9(b) a top view; and FIG. 9(c) a sectional viewof the needle cut along line A-A′ in FIG. 9(b). The length of the needlebody 1 may be appropriately adjusted to give the most therapeutic effectwhen it is inserted through the guide tube 3 as far as possible.

FIGS. 10(a), (b), (c) and (d) show the stoppers attached to the needlehandle 2, and their relation to the needle handle 2 , and represent anembodiment different from the one shown in FIG. 9. FIG. 10(a) shows anembodiment of the needle in which a portion of the stopper protrudesfrom the lowest end of the needle handle 2; FIG. 10(b) anotherembodiment of the needle in which the flange-like stopper is pluggedbeneath the lowest end of the needle handle 2; and FIG. 10(c) a stillfurther embodiment of the needle in which the stopper wraps around thelowest end of the needle handle 2; and FIG. 10(d) is a still furtherembodiment of the needle of which the needle handle 2 has the bulged rimat its lowest end to serve as the stopper.

FIG. 11 shows an embodiment of the needle which has the stopper 255 onthe upper portion of its needle body 1 below the needle handle 2. Thisstopper 255 may be shaped like a clip.

If the safety needle is exclusively used for therapy, besidesdouble-blind test, the stuffing holding needle body 4 may only movablyhold the needle body, and should preferably give smaller resistanceduring passage of the needle body therethrough than that fordouble-blind test. Moreover, it is preferable that the guide tube 3 hasless diameter and less weight, and the distance S1 is made shorter. Asafety needle having such properties as described above is easilyinserted by tapping; its guide tube 3 is light; and thus it is easilyused as in-situ needle.

FIG. 2 shows how the safety needle of FIG. 1 is inserted through theskin into the human body 6. The needle body 1 is so prepared as to makeits length equal to the sum of the length of the guide tube 3 and thedistance (depth) for needle insertion into the human body 6. Thepractitioner holds the guide tube 3 with his left hand, and gives arotatory or thrusting movement onto the needle handle 2 with his righthand.

Thus, he can make the point 9 of the needle body 1 reach a target pointin the human body 6 with twirling or simple insertion technique, withoutdirectly touching the needle body 1. For removing the needle, thepractitioner similarly holds the guide tube 3 with his left hand, andgives a rotatory or simple extracting movement onto the needle handle 2with his right hand, thereby removing the needle without directlytouching the needle body 1. At the time when the safety needle isremoved, a larger portion of the needle body 1 including the point 9remains within the guide tube 3 roughly corresponding with the imageshown in FIG. 1. As seen from above, the safety needle of the presentinvention prevents the practitioner or the disposer for used needle fromdirectly contacting with the needle body 1 and its tip 9, during storageand therapy as well as after removal, and thus it exhibits no risk ofinfection.

Placebo Needle

FIG. 3 shows the placebo needle of the present invention before use:FIG. 3(a) is a frontal view; FIG. 3(b) a top view; and FIG. 3(c) asectional view of the needle cut along line B-B′ in FIG. 3(b). In thisfigure, a guide tube 13 is preferably made of a material to make theirinterior invisible from outside; and in its inner space is plugged andfixed a stuffing holding needle body 14 which gives appropriateresistance to the needle body 14 advancing through the space and holdsthe needle body 14. The stuffing holding needle body 14 placed on thetop end of the guide tube 13 may have its upper surface flush with thetop end of the guide tube 13 so that it can also serve as the stopper.Alternatively, the stuffing holding needle body 14 may have its uppersurface protruding from the top end of the guide 13. In this case, theprotruding portion of the stuffing holding needle body 14 may also serveas the stopper 15. The stuffing holding needle body 14 also serving asthe stopper will be called a needle body holding stopper means.

Such a needle body holding stopper means should be preferably shapedlike a film, a sheet, a plate, a bulk, a cylinder, etc., and have thediameter not larger than the outer diameter of the guide tube 13. Thefirst stuffing 14 is preferably made of the same material as used forthe safety needle. The length of the first stuffing 14 and its numbermay be adjusted appropriately to usage patterns. The first stuffing 14may be made of a laminated body comprising multiple layers composed ofdifferent materials.

At the lower internal cavity of the guide tube 13, there is plugged andfixed the second stuffing 17. The second stuffing 17 gives the sameresistance that can be experienced by the practitioner when he insertsthe needle body into the skin and advances the needle body into thehuman body. The length of the second stuffing 17 and its number may beadjusted appropriately to usage patterns. The second stuffing 17 may bemade of a laminated body comprising multiple layers composed ofdifferent materials. The second stuffing 17 may be made of a cotton, asponge, plastics, a silicone resin, a rubber, a polysaccharide, aprotein, a synthetic chemical sponge, foamed plastics, a syntheticfiber, a natural fiber, a raw meat from livestock/fish, a processed meat(ham, etc.), an electrically conductive paste, an electricallyconductive gel alone or in combination. The point 19 of the needle body11 advances to a point apart from the upper end of the second stuffing17 by a distance S2. If this needle is used for double-blind test, S2 ismade equal to S1 (S2=S1).

The needle handle 12 is attached to the upper end of the needle body.The guide tube 13 has on its top end a stopper 15 to prevent the entryof the lowest end of handle 12 into the guide tube 13. The stopper 15may be placed outside or inside of the guide tube 13. If the stopper 15is placed outside the guide tube 13, it may movably hold the needle bodyin such a way as to allow the needle body to pass along the central axisand have a material to give resistance, during its passage through thestopper 15, which is approximately the same as the resistance as that bythe stuffing holding needle body 14 during the needle body pass throughas described above in relation with the safety needle. The stopperhaving such functions as described above will be called a “needle bodyholding stopper means.” The lower stuffing (the second stuffing) in aplacebo needle with a needle body holding stopper means will be called a“stuffing giving skin puncture like sensation.”

Such a stopper 15 should be preferably shaped like a film, a sheet, aplate, a bulk, a cylinder, a clip, etc., and have a diameter not largethan the outer diameter of the guide tube 13. The stopper 15 may beplaced at the lower end of the needle handle 12, instead of at the sideof the guide tube 13. FIG. 12 shows the placebo needle of the presentinvention before use having the stopper 35 attached to the lowest end ofthe needle handle 12: FIG. 12(a) is a frontal view; FIG. 12(b) a topview; and FIG. 12(c) a sectional view of the needle cut along line B-B′in FIG. 12(b).

The embodiments of the stopper of the placebo needle may take the sameconfigurations (figures being omitted here) as those of the safetyneedle that are shown in FIGS. 10 and 11.

FIG. 4 shows how the placebo needle of FIG. 3 is applied onto the humanskin surface 16.

If the first stuffing is made of a material which has resistance tocancel resistance the practitioner would feel when he inserts the needlebody into the skin, and advances the needle body through the skin, iftherapy is practiced by the amateur acupuncturist or the practitionerunaccustomed to the technique, if shallow insertion of the safety needleis required, if the patient has the thin and soft skin, or if the needleis applied to the soft subcutaneous tissue in the portion a needleapplied, the second stuffing 17 may be omitted.

Pedestal

FIG. 5 shows the safety needle of FIG. 1 having the pedestal 8 attachedto its lowest end. The pedestal 8 has adhesive materials or a suckingdisk on its undersurface to firmly stick to the human skin surface byadhesion or suction. FIG. 5(a) is a frontal view; FIG. 5(b) a top view;and FIG. 5(c) a sectional view of the needle cut along line C-C′ in FIG.5(b). The pedestal 8 may be integratively united with the guide tube 3,or it may be separately prepared and then united removably with theguide tube 3. Alternatively, the guide tube 3 may have the adhesiveundersurface to be suitably used as in-situ needle, instead of havingthe pedestal 8 on its bottom end.

Such a means is useful when the safety needle is used for therapy.

FIG. 6 shows how the safety needle of FIG. 5 is inserted through theskin into the human body 6. As shown in the FIG. 6, because the guidetube 3 has the adhesive or sucking pedestal 8, it is stabilized on theskin surface during therapy, and keeps the needle body 1 to be stablyinserted for an arbitrary period (in-situ needle).

If a safety needle is deeply inserted, and the length of the guide tube3 and the length and diameter of the needle body are appropriatelyadjusted, the safety needle does not necessarily require the use of thepedestal 8 to serve as in-situ needle. However, if a needle must beshallowly inserted in spite of its being used as in-situ needle, if aninserted needle must be stabilized, or if a needle is used forelectroacupuncture, the safety needle should be preferably used incombination with the pedestal 8.

FIG. 7 shows the placebo needle of FIG. 3 having the pedestal 18attached to its lowest end. The undersurface of the pedestal 18 hasadhesive materials or a sucking disk on its undersurface to firmly stickto the human skin surface by adhesion or suction. FIG. 7(a) is a frontalview; FIG. 7(b) a top view; and FIG. 7(c) a sectional view of the needlecut along line D-D′ in FIG. 7(b). The pedestal 18 may be integrativelyunited with the guide tube 13, or it may be separately prepared and thenunited removably with the guide tube 13.

FIG. 8 shows how the placebo needle of FIG. 7 is applied onto the skinsurface of the human body 16. As shown in the FIG. 8, because the guidetube 13 has the adhesive or sucking pedestal 18, it is possible tostably place the placebo needle containing the guide tube 13 onto theskin.

If both the safety needle and the placebo needle are used with theadhesive or sucking pedestal 8 or 18, it can be easy to maintain theirbeing used as in-situ needles (needle body is inserted into the humanbody and kept there for an arbitrary period).

Lowest Ends of a Safety Needle and a Placebo Needle

When it is necessary to insert a safety needle obliquely onto the humanskin surface, it is better to use the guide tube 3 having its bottom endcut obliquely as shown in FIG. 13. Similarly for a placebo needle, theguide tube 13 should preferably have its bottom end cut obliquely asshown in FIG. 14. For the guide tube 3 and 13 shown in FIGS. 13 and 14whose bottom ends have been cut obliquely, their length is determined bymeasuring along the central axis. When it is necessary to attach thepedestal to the obliquely cut end of the guide tube 3 and 13, thepedestal should be adjusted of its form to fit the form of the cut endof the guide tube 3 and 13.

Needle Set for Double-blind Test

A safety needle and a placebo needle as described above may be combinedinto a set for double-blind test. For this purpose, the two kinds of theneedles should be made the same in appearance with each other: thelengths of the guide tube 3 and 13, the lengths of the needle bodyprotruding from the top end of the guide tube 3 and 13, and the lengthsof the needle handle 2 and 12 of the two kinds of the needles must bethe same; and the distance S₁ from the point 9 of the needle bodycontained in the safety needle to the skin surface must be the same asthe distance S₂ from the point 19 of the needle body 11 contained in theplacebo needle to the upper surface of the second stuffing 17. In short,the two kinds of the needles must be the same in shape and color.

The stuffing holding needle body 4 contained in the safety needle andthe first stuffing 14 contained in the placebo needle should bepreferably made of the same material, and the guide tube 3 and 13 shouldbe preferably made opaque to make their interior invisible from outside.And, it is preferable that the guide tubes 3 and 13 may have theirbottom ends covered with covers (not illustrated here) to make theirinterior invisible from outside. The cover should be sterilized inadvance, shaped like a film, a sheet, a plate, or a bulk, and made of analcohol-soaked cotton, a sponge, a synthetic chemical sponge, plastics,a paper, a gauze, a protein, or a polysaccharide alone or incombination. The cover may be substituted for electro-conductive paste(applied to the end of the guide tube to form a cover), an electricallyconductive jelly, or an electrically conductive pad.

If, before a safety needle and a placebo needle are used, each needlebody 1 and 11 is marked at the same position as the top end of the guidetube 3 and 13(including the thickness of the stopper protruding from thetop end of the guide tube), it will be easy to replace the needle body 1and 11 to the positions before use, after therapy.

The total length of the guide tubes 3 and 13 should be made equal to thelength that the length of the needle body of the safety needle minusthat of the desired insertion depth. If the guide tubes 3 and 13 havethe stoppers on its outside, the height of stopper should be added tothe minus term. The insertion depth may vary according to the site to betreated, and thus the length of the guide tube 3 and 13 should beadjusted appropriately.

When the bottom end of the needle handles 2, 12 reach at the top end ofthe guide tubes 3 or 13, the needle bodies I or 11 are prevented fromadvancing further because of the stoppers 5, 15, 25 or 35 placed on thetop end of the guide tubes 3 or 13, or on the lowest end of the needlehandles 2 or 12 of the two kinds of the needles. Thus, if the length ofthe needle body 11 of the placebo needle is equal to that of the guidetube 13, the possible moving distances of the needle bodies 1 and 11 arethe same for their application, the distances the needle body 1 and 11move will be the same in application of the two kinds of the needle. Ifthe needle body 11 of placebo needles is made slightly longer or shorterthan the guide tube 13, the distances passed through of the two kinds ofthe needles will be about the same.

The safety needle will be inserted into the human body by a distanceequal to the length that the needle body 1 minus the length of the guidetube 3. If the guide tube 3 has the stopper 5 on its outside, the heightof the stopper 5 should be added to the minus term. The length of theneedle body 11 of the placebo needle should be adjusted such that thepoint 19 of the needle body 11 falls in a range from a position at whichthe needle point 19 can give pressure on the skin to a position just onthe skin surface, at the moment when the needle body 11 is stopped bystoppers 15 or 35 during needle insertion by twirling or simpleinsertion with the Sashide. To obtain a placebo needle having suchlength as described above, it is recommended to cut its needle body 11at a point so that its length is slightly longer or shorter than thelength of the guide tube 13. The point 19 of the needle body 11 shouldpreferably have form impenetrable to the skin (for example, having ablunt tip). The length of the needle body 11 and shape of the point 19of the needle body 11 a of the placebo needle may be varied according tothe desired intensity of stimulation with that needle.

Because both the safety needle and placebo needle have the guide tubes 3and 13 which have stuffings holding needle body 4 and 14 (first stuffingfor the placebo needle) plugged and fixed within their cavities, theneedle bodies 1 and 11 receive resistance against the motion in thestraight direction or the rotary motion of the needle bodies 1 and 11during needle insertion or needle removal. The intensity of resistancemay be adjusted appropriately according to the usage patterns, treatmentmethod, the point to be treated and the insertion depth. Becausesensation from this resistance cancels the sensation of resistance whichthe practitioner experiences through his Sashide when he inserts orremoves the needle into or from the body, the practitioner can notdistinguish a safety needle from a placebo needle.

Furthermore the guide tube 13 of a placebo needle has the secondstuffing 17 plugged and fixed in its cavity. The second stuffing 17 maybe plugged and fixed at a position such that its lower surface is closeto or corresponds to the position of the bottom end of the guide tube13. On the other hand, the upper surface of the second stuffing 17 is ata position higher than the bottom end of the guide tube 13 by an amountequal to the difference between the length of the needle body of thesafety needle and that of the corresponding placebo needle (or equal tothe depth by which the needle body 1 of the safety needle is insertedinto the human body 6). In application of the safety needle and theplacebo needle of which the guide tube 13 has the second stuffing 17arranged as above, the portions of the needle body 1, 11, and of handle2, 12 protruding from the guide tube 3, 13 are made equal in lengthbetween two kinds of the needles; and then the distance S₁ i.e. thedistance passed through from the point 9 of the needle body 1 of thesafety needle to the skin surface becomes equal to the distance S₂ i.e.the distance passed through from the point 19 of the needle body 11 ofthe placebo needle to the upper surface of the second stuffing 17plugged and fixed at the bottom end of the guide tube 13 (S₁=S₂),provided that the length of the needle body 11 of the placebo needle isthe same as that of the guide tube 13. If the length of the needle body11 of the placebo needle is slightly less or more than the length of theguide tube 13, the distances passed through of the needle body 1 and 11will become nearly equal.

A needle set in which the safety and placebo needles are related to eachother in the manner as described above, is applied to human body 6,16:when the point 19 of the needle body 11 of the placebo needle advancesby distance equal to S₁ or distance from the point 9 of the needle body1 of the safety needle to reach the skin surface, it reaches the uppersurface of the second stuffing 17; and thus when the point 19 of theneedle body 11 of the placebo needle advances further, the needle stemreceives resistance from the second stuffing 17 equal to the resistancethat by the needle stem 1 of the safety needle may be receive when itreaches the skin and advances through the human body 6. Accordingly, thepractitioner feel difficulty in distinguishing the two kinds of theneedle during execution of therapy, and thus this needle set enable tomask the practitioner.

With such a needle set as above, if the first stuffing is made of amaterial which has resistance to cancel resistance the practitionerfeels when he inserts a needle body into the skin and advances itthrough the skin, if therapy is practiced by an amateur acupuncturist ora practitioner unaccustomed to the needling technique, if shallowinsertion of a safety needle is required, if the patient has the thinand soft skin, or if the needle is be applied to the soft subcutaneoustissue, the second stuffing 17 may be omitted. But if needlingtechniques other than simple insertion or in-situ needle such as sparrowpecking, needle twirling technique, etc. are required, it is preferableto apply the second stuffing, because the first stuffing must have lowerresistance than that in the case of simple insertion or in-situ needle.

Another method to mask the difference between a safety needle and aplacebo needle is as follows. A group of the safety needles is preparedby selecting, according to the purpose of given double-blind test,appropriate ones different in one or more features from among the safetyneedles that are different in the material of the needle handle, length,color, or shape; in the material of the needle body, total length,diameter, length protruding from the top end of the guide tube or fromthe upper end of the needle body holding stopper means, distance fromits point to the skin, or insertion depth; in the material of the guidetube, length, color or shape; and in the material of the stuffingholding needle body, quantity, number or position.

Another group comprising placebo needles is prepared by selecting,according to the purpose of given double-blind test, appropriate onesdifferent in one or more features from among the placebo needles thatare different in the material of the needle handle, length, color orshape; in the material of the needle body, total length, diameter, orlength protruding from the top end of the guide tube or from the upperend of the needle body holding stopper means, the distance from thepoint to the upper surface of the second stuffing; in the material ofthe guide tube, length, color or shape; in the material of the firststuffing holding needle body, the quantity, the number or the position;and in the material of the second stuffing, its quantity, number orposition.

Next, the groups of the safety needles and placebo needles that aredifferent in one or more features are combined into a needle set fordouble-blind test. The individual safety needle and placebo needle thathave been selected as above to be different in one or more features arecombined to give a needle set for double-blind test. Thus, the safetyneedle and placebo needle thus combined can not be distinguished fromappearance by the practitioner or by the subject, because itscombination is randomly formed according to the purpose ot givendouble-blind test. The use of those needles will ensuredouble-blindness.

Needle Set for Double-blinding the Diameter of the Needle Body

When combining needles as above to prepare a needle set for double-blindtest, attention is paid, for example, to the diameter of the needle.Selecting safety needles and placebo needles different in diameter, andcombining them into various pairs of the safety and placebo needles thatare the same in appearance, though being different in diameter. Then, itis possible to carry out double-blind test masking the diameter of theneedles from the practitioner and the subject. The needle set comprisingsuch a combination of the needles will be called a needle set fordiameter double-blinding the diameter of the needle body.

Needle Set for Double-blinding the Depth of the Needle Body

When combining needles as above to prepare a needle set for double-blindtest, attention is paid, for example, to the insertion depth of theneedle body. Selecting safety needles different in insertion depth ofthe needle body, and placebo needles different in the length of theneedle body, and combining them into various pairs of the safety andplacebo needles that are the same in appearance, though being differentin length. Then, it is possible to carry out double-blind test maskingthe insertion depth of the needle body from the practitioner and thesubject. The needle set comprising such a combination of the needle bodywill be called a needle set for depth double-blinding.

Another needle set for depth double-blinding whereby insertion depth canbe double-blinded is described below.

Such a needle set comprises depth masking needles which are different ininsertion depth. The group of the needle set for depth double-blindingcomprises the needles that are different in insertion depth as well asin the guide tube length, and another group of the needle set for depthdouble-blinding comprises the needle bodies that are different ininsertion depth, although their guide tube length is the same. The guidetube is preferably made opaque to make their interior invisible fromoutside.

i) Needle set comprises needles which are different in insertion depthas well as in guide tube length.

This type of depth double-blind needle set comprises, as the firstgroup, depth masking needles that have following elements (1) to (4),and are different in insertion depth as well as in guide tube length.Thus, each of the depth masking needle classified to the first group mayhave the same shape as that of the safety needle as depicted in FIG. 1,and comprises: (1) a guide tube; (2) one or more stuffings holdingneedle body which is plugged and fixed at a desired position in thecavity of the guide tube, gives resistance during passage of the needlebody therethrough, and holds the needle body; (3) the needle bodymovably held by the stuffing and the needle body is longer than theguide tube by an amount equal to the insertion depth of the needle body;and (4) the stopper which is placed on the lowest end of the needlehandle attached to the top end of the needle body, or on the top end ofthe guide tube, and serves as the stopper to prevent the needle handlefrom entering into the guide tube at the moment when the point of theneedle body reaches to a specified insertion depth. If the needle setfor depth double-blind test comprises only the first group of depthmasking needles, the stuffing holding needle body should preferably giveresistance sufficiently large to cancel resistance that by the needlebody may be received when it reaches the skin surface and penetratesinto the human body.

The depth double-blind needle set as above may comprise needles whichhave the needle body holding stopper means, instead of the stuffingholding needle body and the stopper. The needle body holding stoppermeans is placed on the top end of the guide tube, prevents the needlehandle from entering into the guide tube when the point of the needlebody reaches to the specified insertion depth, and thus not only holdsthe needle body but gives resistance to it during its passage therethrough.

When such a needle set for depth double-blind test as described above isused for double-blind test, the needles are different in the length ofthe guide tube, the length of the needle body relative to the length ofthe guide tube, the length of the needle body protruding from the topend of the guide tube, and the insertion depth of the needle body, andthus neither the practitioner nor the subject can know from appearancethe insertion depth of any given needle. The practitioner could not tellwhether any given needle is a safety needle or a placebo needle, fromthe sensation which he received when he inserts the needle body into theskin and advances through human body, and he could not tell theinsertion depth of that needle. Thus, the insertion depth is doublyblinded.

A still further second group of depth double-blind needle set which isdifferent in the length of the guide tube, and in the insertion depth ofthe needle body is obtained by plugging the stuffing at the lower end ofthe guide tube that can give similar resistance that by the needle bodymay be received when it reaches the skin surface and penetrate into thehuman body, during passage of the needle body therethrough. Namely, thedepth masking needle set for double-blind test comprises: (1) a guidetube; (2) one or more stuffings holding needle body which is plugged andfixed at a desired position in the cavity of the guide tube, givesresistance to the needle body during its passage therethrough, and holdsthe needle body; (3) one or more stuffings giving skin puncture likesensation which is plugged and fixed at a lower position in the cavityof the guide tube, and gives the similar sensation to the skin punctureand tissue penetration while the needle body advances through the cavityof the guide tube to reach to the specified depth; (4) the needle bodymovably held by the stuffing and the needle body is longer than theguide tube by an amount equal to the insertion depth of the needle body;and (5) a stopper which is placed on the lowest end of the needle handleattached to the top end of the needle body, or on the top end of theguide tube, and serves as the stopper to prevent the needle handle fromentering into the guide tube at the moment when the point of the needlebody reached to the specified insertion depth.

The depth masking needle set may comprise needles which have a needlebody holding stopper means, instead of a stuffing holding needle bodyand a stopper. The needle body holding stopper means is placed on thetop end of the guide tube, prevents the needle handle from entering intothe guide tube when the point of the needle body reaches to thespecified insertion depth, and thus not only holds the needle body butgives resistance to it during its passage therethrough.

When such a needle set for double-blind test as described above is usedfor depth double-blind test, the needles are different in the length ofthe guide tube, the length of the needle body relative to the length ofthe guide tube, the length of the needle body protruding from the topend of the guide tube, the length of stuffing giving skin puncture likesensation, and the insertion depth of the needle body, and thus neitherthe practitioner nor the subject can know from appearance the insertiondepth of any given needle. The practitioner could not tell whether anygiven needle is a safety needle or a placebo needle, from the sensationswhich he received when he inserts the needle body into the skin and thehuman body, and he could not tell the insertion depth of that needlebody. Thus, if a needle is randomly selected from those depth maskingneedles, and applied to the subject, it will be possible to blind boththe practitioner and the subject to the insertion depth of that needle.

Further, if two or more needles are randomly selected one half from thefirst group of the depth masking needles and the other half from thesecond group of the depth masking needles, and combined, they will givethe needle set for double-blind test with which it is possible to blindthe insertion depth of the needle body.

The stuffing holding needle body to be applied to the depth maskingneedle may be made of the same material as used in the safety needle, oras used for the first stuffing of the placebo needle.

The stuffing giving skin puncture like sensation to be applied to thedepth masking needle may be made of the same material as used for thesecond stuffing of the placebo needle, provided that it poses nosanitation problem. The stuffing giving skin puncture like sensation maybe made of, for example, alcohol-soaked cotton, and its length anddensity, and the position in the cavity of the guide tube may beadjusted appropriately according to the usage pattern. Thealcohol-soaked cotton may be divided into two or more portions for use.Instead of alcohol-soaked cotton, the stuffing may be made of othersterilized material (material which will not pose any sanitationproblem, even when the point and needle body penetrates the body afterpassing through that material, for example, alcohol-soaked gauze orpaper).

ii) Needles which are the same in the length of the guide tube, thelength of the needle body protruding from the top end of the guide tube,and the length of the needle handle, but different in insertion depthare combined to form a depth double-blind needle set.

Of the needle set for depth double-blind test containing both thestuffing holding needle body and the stuffing giving skin puncture likesensation as described above in the second group of i) those that arethe same in the length of the guide tube, the length of the needle bodyprotruding from the top end of the guide tube, and the length of theneedle handle, but different in insertion depth are selected, andcombined into a depth double-blind needle set. The position of stuffinggiving skin puncture like sensation (the lowest stuffing) of all thestuffings should be preferably determined according to the needle whichhas the largest insertion depth in that group. The distance from theupper surface of the stuffing to the point of the needle body of othershorter needle than the longest needle should be preferably equal to thedistance from the upper surface of the stuffing to the point of theneedle body of the longest needle with which the insertion length is thedeepest. The first group of the needles as mentioned in paragraph i) maybe used as the needle set as described above.

Needle Set for Double-blinding the Acupoint

If it is necessary to make the practitioner unaware of whether a needleis applied to an acupoint or the non-acupoint, the third person mayplace a needle assembly with the pedestal of this invention (the safetyneedle or the placebo needle) at an acupoint or a nonacupoint to enableapplication, and then the practitioner inserts the needle there. In thiscase, the needle assembly with pedestal will enable this invention maskthe point for needle application(whether it is an acupoint or anon-acupoint) from the practitioner as well as the subject.

Therapy With a Safety Needle

To practice therapy with the safety needle of this invention, thepractitioner first inserts the guide tube 3 of the safety needle betweenthe pads of thumb and index finger of Oshide being formed on the skin;holds the guide tube 3; taps the top end of the needle handle 2 by theSashide (hand to advance or remove a needle) to penetrate the skin withthe point 9 of the needle body 1; advances by twirling or by simpleinsertion technique until it is stopped by the stopper 5 or 25 placed onthe lower end of the needle handle 2 or on the top end of the guide tube3; and just at that moment the point 9 of the needle body 1 reaches adesired position in the human body 6. Needle insertion may be performedby twirling technique without tapping the top end of the needle handle 2by the Sashide depending on the intensity of resistance given by thestuffing holding needle body 4 during passage of the needle body 1therethrough, or on the length of the needle body 1 protruding from thetop end of the guide tube. Therapy with in-situ needle consists ofleaving the inserted needle for an arbitrary period. When a therapy within-situ needle is practiced, it is preferable to apply the safety needlewith the pedestal on the skin, because it will be easy to maintain therethe in-situ needle. Then, practitioner holds the guide tube by Oshide,and removes the needle until the needle replace the original position bySashide. When the safety needle has the guide tube with the pedestal ofthis invention, Oshide will not be required. At this stage, the part ofthe needle body 1 which has been inserted into the human body 6 is putback into the cavity of the guide tube 3. The guide tube 3 containingthe needle body 1 in the manner as described above is removed from thehuman body 6, and is discarded into a specified container.

Industrial Applicability

In the present invention, the tip of the needle body as the component ofthe safety needle is contained in the cavity of a guide tube as thecomponent of the safety needle, during storage, therapy and post-therapyperiod. The needle body is not separated from the guide tube at anytime. Therefore, the acupuncture therapist and disposer for the useand/or disposal of the needle are protected against direct exposure tothe needle body and its point. This indicates that a person who handlean acupuncture needle can be free from the risk of infection from thepatient to the practitioner, from the practitioner to a third person, bydamaging themselves by accident with the contaminated needle andexposure to infection of the practitioner and the disposer who mightotherwise contaminate themselves by damaging themselves by accident withthe needle.

With the safety needle of the present invention, it is possible toprevent by the needle body which has reached a desired depth fromadvancing further by a stopper. Through this arrangement, it is possibleto minimize unnecessary damages to a tissue or to an important organ.This is particularly important when therapy is applied to the thorax orthe abdomen, because the thorax and the abdomen contain many importantorgans, and thus to apply therapy there the precise placement of aneedle is required. In therapy with a conventional needle, thepractitioner determines the insertion depth of the needle depending onhis subjective impression or feeling, he might insert the needle byaccident deeper than is necessary, or stop it before reach. Therapy within-situ needle may present problems: the needle advances inadvertentlydeeper than is desired, as a result of the weight of the needlebody/handle themselves, or of an object such as the towel placed on theneedle, or of the muscle contraction. The safety needle of thisinvention is free from those problems because it has the stopper.

The needle set of this invention for double-blind test makes it possiblefor the first time to carry out double-blind test for strictlyevaluating the therapeutic effect of acupuncture in which both thepractitioner and the subject are blinded whether a real needle or aplacebo needle are used.

When the safety needles the needle bodies of which are different in thelength of the guide tube and in the length of the needle body relativeto the length of the guide tube are used for therapy, it is possible tocarry out double-blind test in which the insertion depth of the needleis masked.

When the safety needles are used for therapy the needle bodies of whichare different in the diameter of the needle body, it is possible tocarry out double-blind test in which the diameter of the needle body canbe masked.

Because the safety needle and the placebo needle of this invention aremovably held by the stuffing in the cavity of the guide tube, it ispossible to straightly move the needle during needle insertion or needleremoval, and thus the guide tube also serves as Oshide. When an adhesivepedestal is attached, it is possible to stabilize the needle (safetyneedle or placebo needle) being kept in the guide tube, which maydispense with Oshide.

The needle assembly with the pedestal will enable this invention to maskthe point for needle application masking the nature of site (whether itis an acupoint or a non-acupoint) from the practitioner as well as thesubject.

What is claimed is:
 1. A safety needle comprising: (1) a guide tube; (2) one or more stuffings holding needle body which are plugged into the guide tube to be fixed at a desired position, to give resistance to a needle body during its passage therethrough, and to hold the needle body; (3) the needle body movably held by the stuffing which has the length longer than that of the guide tube by an amount equal to the insertion depth of the needle body; and (4) a stopper which is mounted to the lower end of a needle handle attached to the top of the needle body, or which is mounted to the top end of the guide tube, and prevents the needle handle from advancing further at the moment when the needle point reach a specified insertion depth; (5) wherein the guide tube is longer than the insertion depth of the needle body.
 2. A safety needle comprising: (1) a guide tube; (2) a needle body holding stopper means which is mounted outside the top end of the guide tube, and which prevents a needle handle from advancing further into the guide tube when the point of the needle body reaches a specified insertion depth, and not only holds the needle body but gives resistance to it during its passage therethrough; and (3)the needle body movably held by the needle body holding stopper means which has the length longer than the distance from the end of the guide tube in contact with the skin to the end of the needle body holding stopper means to be in contact with the needle handle by an amount equal to the insertion depth of the needle body, (4) wherein the distance from the end of the needle body holding stopper means to be in contact with the needle handle from the end of the guide tube to be in contact with the skin is larger than the insertion depth of the needle body.
 3. A safety needle as described in claim 1 or 2 wherein the guide tube has an adhesive or a sucking pedestal on the surface of its base to be in contact with the skin.
 4. A placebo needle comprising: (1) a guide tube; (2) one or more first stuffings which are plugged into the guide tube to be fixed at a desired position, to give resistance to a needle body during its passage therethrough, and to hold the needle body; (3) one or more second stuffings which are plugged into lower position of the guide tube and fixed, to give similar sensation to the skin puncture and the tissue penetration during passage of the needle body therethrough to reach a specified depth; (4) the needle body movably held by the first stuffing which has the length sufficiently long to allow its point to stop at a position prior to penetrating the skin surface when the needle body is advanced through the cavity of the guide tube as far as possible; and (5) a stopper which is mounted to the lower end of the needle handle attached to the top of the needle body, or which is mounted to the upper end of the guide tube, and prevents the needle handle from advancing further into the guide tube when the point of the needle body reaches the position prior to penetrating the skin surface.
 5. A placebo needle comprising: (1) a guide tube; (2) a needle body holding stopper means which is mounted outside the top end of the guide tube, and which prevents the needle handle from advancing further into the guide tube when the point of the needle body reaches a position prior to penetrating the skin surface, and not only holds the needle body but gives resistance to it during its passage therethrough; (3) one or more stuffings giving skin puncture like sensation which are plugged into the guide tube to be fixed at a lower position, to give sensations indicative to the skin puncture and the tissue penetration during passage of a needle body through the cavity of the guide tube to reach the specified depth; and (4) the needle body movably held by the needle body holding stopper means which has the length sufficiently long to allow its point to stop at the position prior to penetrating the skin surface when the needle body is advanced through the cavity of the guide tube as far as possible.
 6. A placebo needle comprising: (1) a guide tube; (2) one or more stuffings holding needle body which are plugged into the guide tube to be fixed at a desired position, to give resistance to the needle body during its passage therethrough; (3) the needle body movably held by the stuffing holding needle body which has the length sufficiently long to allow its point to stop at a position prior to penetrating the skin surface when the needle body being advanced through the cavity of the guide tube as far as possible; and (4) a stopper which is mounted to the lower end of a needle handle attached to the top of the needle body, or which is mounted to the top end of the guide tube, and prevents the needle handle from advancing further into the guide tube when the point of the needle body being advanced through the cavity of the guide tube reaches the position prior to penetrating the skin.
 7. A placebo needle comprising: (1) a guide tube; (2) a needle body holding stopper means which is mounted outside the top end of the guide tube, and which prevents a needle handle from advancing further into the guide tube when the point of the needle body reaches a position prior to penetrating the skin surface, and not only holds the needle body but gives resistance to it during its passage therethrough; and (3) the needle body movably held by the needle body holding stopper means which has the length sufficiently long to allow its point to stop at the position prior to penetrating the skin surface when the needle body is advanced through the cavity of the guide tube as far as possible.
 8. A placebo needle as claimed in claim 4, 5, 6 or 7 wherein the point of the needle body takes a form impenetrable to the body.
 9. A placebo needle as claimed in claim 4, 5, 6 or 7 wherein the guide tube has an adhesive or sucking pedestal on the surface of its base to be in contact with the skin.
 10. Needle set for double-blinding depth obtained by combining two or more needles selected one from a first group of depth masking needles and the other from a second group of depth masking needles, the first group comprising plural masking needles each of which includes: (1) a guide tube; (2) one or more stuffings holding needle body which are plugged into the guide tube to be fixed at a desired position, to give resistance during passage of a needle body therethrough, and to hold the needle body; (3) the needle body movably held by the stuffing which has length longer than that of the guide tube by an amount equal to the insertion depth of the needle body; and (4) a stopper which is mounted to the lower end of a handle attached to the top of the needle body, or to the top end of the guide tube, and prevents the needle handle from advancing further into the capacity of the guide tube when the point of the needle body reaches a specified insertion depth, (5) wherein those plural depth masking needles are different in the length of the guide tube, the length of the needle body relative to the length of the guide tube, the length of the needle body protruding from the top end of the guide tube, and the insertion depth of the needle body; and the second group comprising plural masking needles each of which includes: (6) a guide tube; (7) one or more stuffings holding needle body which are plugged into the guide tube to be fixed at a desired position, to give resistance during passage of a needle body therethrough, and to hold the needle body; (8) one or more stuffing giving skin puncture like sensations which are plugged into the guide tube to be fixed at a lower position, to give similar sensation to the skin puncture and the tissue penetration during passage of the needle body through the cavity of the guide tube to reach a specified depth; (9) the needle body movably held by the stuffing holding needle body which has length longer than that of the guide tube by an amount equal to the insertion depth of the needle body; and (10) a stopper which is mounted to the lower end of a needle handle attached to the top of the needle body, or to the top end of the guide tube, and prevents the needle handle from advancing further into the cavity of the guide tube when the point of the needle body reaches a specified insertion depth, (11) wherein those plural depth masking needles are different in the length of the guide tube, the length of the needle body relative to the length of the guide tube, the length of the needle body protruding from the top end of the guide tube, the length of the stuffing giving skin puncture like sensation, and the insertion depth of the needle body.
 11. A needle set for double-blinding depth obtained by combining two or more needles selected one from a first group of depth masking needles and the other from a second group of depth masking needles, the first group comprising plural masking needles each of which includes: (1) a guide tube; (2) a needle body holding stopper means which is mounted outside the top end of the guide tube, and which prevents a needle handle from advancing further into the cavity of the guide tube when the point of a needle body reaches a specified insertion depth, and not only holds the needle body but gives resistance to it during its passage therethrough; and (3) the needle body movably held by the stuffing which has length longer than the distance from the end of the guide tube to be in contact with the skin to the end of the needle body holding stopper means to be in contact with the needle handle by an amount equal to the insertion depth of the needle body, (4) wherein those plural depth masking needles are different in the length of the guide tube, the length of the needle body relative to the length of the guide tube, the length of the needle body protruding from the top end of the guide tube, and the insertion depth of the needle body; and the second group comprising plural masking needles each of which includes: (5) a guide tube; (6) a needle body holding stopper means which is mounted outside the top end of the guide tube, and which prevents a needle handle from advancing further into the cavity of the guide tube when the point of the needle body reaches a specified insertion depth, and not only holds the needle body but gives resistance to it during its passage therethrough; (7) one or more stuffing giving skin puncture like sensations which are plugged into the guide tube to be fixed at a lower position, to give similar sensations to the skin puncture and the tissue penetration during passage of the needle body through the cavity of the guide tube to reach a specified depth; and (8) the needle body movably held by the needle body holding stopper means which has the length longer than the distance from the end of the guide tube to be in contact with the skin to the end of the needle body holding stopper means to be in contact with the needle handle by an amount equal to the insertion depth of the needle body, (9) wherein those plural depth masking needles are different in the length of the guide tube, the length of the needle body relative to the length of the guide tube, the length of the needle body protruding from the top end of the guide tube, the length of the stuffing giving skin puncture like sensation, and the insertion depth of the needle body.
 12. A needle set for double-blinding depth obtained by combining two or more groups comprising depth masking needles each of which comprises: (1) a guide tube; (2) one or more stuffings holding needle body which are plugged into the guide tube to be fixed at a desired position, to give resistance during passage of a needle body therethrough, and to hold the needle body; (3) one or more stuffings giving skin puncture like sensations which are plugged into the guide tube to be fixed at a lower position, to give similar sensation to the skin puncture and the tissue penetration during passage of the needle body through the cavity of the guide tube to reach a specified depth; (4) the needle body movably held by the stuffing holding needle body which has the length longer than that of the guide tube by an amount equal to the insertion depth of the needle body; and (5) a stopper which is mounted to the lower end of a needle handle attached to the top of the needle body, or to the top end of the guide tube, and prevents the needle handle from advancing further into the cavity of the guide tube when the point of the needle body being advanced through the guide tube reaches a specified insertion depth, (6) wherein those plural depth masking needles are different in the length of the guide tube, the length of the needle body protruding from the top end of the guide tube, the length of the stuffing giving skin puncture like sensation, and the insertion depth of the needle body.
 13. Needle set for double-blinding depth obtained by combining two or more groups comprising depth masking needles each of which comprises: (1) a guide tube; (2) a needle body holding stopper means which is mounted outside the top end of the guide tube, and which prevents a needle handle from advancing further into the cavity of the guide tube when the point of the needle body reaches a specified insertion depth, and not only holds the needle body but gives resistance to it during its passage therethrough; (3) one or more stuffings giving skin puncture like sensations which are plugged into the guide tube to be fixed at a lower position, to give similar sensation to the skin puncture and the tissue penetration during passage of the needle body through the cavity of the guide tube to reach a specified depth; and (4) the needle body movably held by the needle body holding stopper means which has length longer than the distance from the end of the guide tube to be in contact with the skin to the end of the needle body holding stopper means to be in contact with the needle handle by an amount equal to the insertion depth of the needle body, (5) wherein those plural depth masking needles are different in the length of the guide tube, the length of the needle body protruding from the top end of the guide tube, the length of the stuffing giving skin puncture like sensation, and the insertion depth of the needle body.
 14. A needle set for double-blind test comprising: (A) a safety needle according to one of a first construction and a second construction wherein: the first construction comprises: (1) a guide tube; (2) one or more stuffings holding needle body which are plugged into the guide tube to be fixed at a desired position, to give resistance to a needle body during its passage therethrough, and to hold the needle body; (3) the needle body movably held by the stuffing which has the length longer than that of the guide tube by an amount equal to the insertion depth of the needle body; and (4) a stopper which is mounted to the lower end of a needle handle attached to the top of the needle body, or which is mounted to the top end of the guide tube, and prevents the needle handle from advancing further at the moment when the needle point reach a specified insertion depth; (5) wherein the guide tube is longer than the insertion depth of the needle body; and the second construction comprises: (1) a guide tube; (2) a needle body holding stopper means which is mounted outside the top end of the guide tube, and which prevents a needle handle from advancing further into the guide tube when the point of the needle body reaches a specified insertion depth, and not only holds the needle body but gives resistance to it during its passage therethrough; and (3) the needle body movably held by the needle body holding stopper means which has the length longer than the distance from the end of the guide tube in contact with the skin to the end of the needle body holding stopper means to be in contact with the needle handle by an amount equal to the insertion depth of the needle body, (4) wherein the distance from the end of the needle body holding stopper means to be in contact with the needle handle from the end of the guide tube to be in contact with the skin is larger than the insertion depth of the needle body; and (B) a placebo needle comprising (1) a guide tube; (2) one or more first stuffings which are plugged into the guide tube to be fixed at a desired position, to give resistance to a needle body during its passage therethrough, and to hold the needle body; (3) one or more second stuffings which are plugged into lower position of the guide tube and fixed, to give similar sensation to the skin puncture and the tissue penetration during passage of the needle body therethrough to reach a specified depth; (4) the needle body movably held by the first stuffing which has the length sufficiently long to allow its point to stop just on or above the skin surface when the needle body is advanced through the cavity of the guide tube as far as possible; and (5) a stopper which is mounted to the lower end of the needle handle attached to the top of the needle body, or which is mounted to the upper end of the guide tube, and prevents the needle handle from advancing further to the guide tube when the point of the needle body reaches just on or above the skin surface.
 15. A needle set for double-blind test according to claim 14 wherein the point of the placebo needle body takes a form impenetrable to a human body.
 16. A needle set for double blind test according to claim 15 wherein the placebo needle guide tube has an adhesive or sucking pedestal on the surface of its base to be in contact with the skin.
 17. A needle set for double-blind test according to claim 15, (1) wherein the safety needle and the placebo needle are the same in their guide tube lengths, or in the distance from the end of the guide tube to be in contact with the skin to the end of the needle body holding stopper means to be in contact with the needle handles, and in the length of their handle, and in the distance from the point of the needle body to the skin surface for the safety needle is the same as the distance from the point of the needle body to the upper surface of the second stuffing or to the upper surface of stuffing giving skin puncture like sensation for the placebo needle; and (2) wherein the upper surface of the second stuffing or of the stuffing giving skin puncture like sensation is placed higher than the bottom end of the guide tube by an amount equal to the insertion depth of the safety needle, and the safety needle and the placebo needle can not be distinguished from their appearances.
 18. A needle set for double-blind test according to claim 15, wherein: the safety needle and the placebo needle are the same in their guide tube length, or in the distance from the end of the guide tube to be in contact with the skin to the end of the needle body holding stopper means to be in contact with the needle handle, in the length of the portion protruding from the top end of the guide tube or from the end of the needle body holding stopper means to be in contact with the needle handle, and in the length of their needle handles; and the safety needle and the placebo needle can not be distinguished from their appearances.
 19. A needle set for double-blind test according to claim 15, comprising: (1) a plurality of the safety needles, the safety needles being different from one another in one or more of the following features: the material, length, color and shape of a needle handle; the material, total length and diameter of a needle body; the length of the needle body protruding from the top end of a guide tube or from the needle body holding stopper means; the distance from the point of the needle body to the skin surface; the insertion depth; the material, length, color and shape of the guide tube; and the material, quantity, number and fixation position of a stuffing holding needle body, and (2) a plurality of the placebo needles, the placebo needles being different from one another in one or more of the following features: the material, length, color and shape of the needle handle; the material, total length and diameter of a needle body; the length of the needle body protruding from the top end of the guide tube or from the needle body holding stopper means; the distance from the point of the needle body to the upper surface of a second stuffing or of a stuffing giving skin puncture like sensation; the material, length, color and shape of the guide tube; the material, quantity, number and fixation position of the first stuffing, and the material, quantity, number and fixation position of the second stuffing or of stuffing giving skin puncture like sensation.
 20. A needle set for double-blind test according to claim 19, wherein the safety needles are different from each other only in diameter of the needle body, the placebo needles are different from each other only in diameter of the needle body, and the safety needles and the placebo needles are combined, thereby masking the diameters of the needle bodies.
 21. A needle set for double-blind test according to claim 14 wherein the placebo needle guide tube has an adhesive or sucking pedestal on the surface of its base to be in contact with the skin.
 22. A needle set for double-blind test according to claim 21, (1) wherein the safety needle and the placebo needle are the same in their guide tube lengths, or in the distance from the end of the guide tube to be in contact with the skin to the end of the needle body holding stopper means to be in contact with the needle handles, and in the length of their handle, and in the distance from the point of the needle body to the skin surface for the safety needle is the same as the distance from the point of the needle body to the upper surface of the second stuffing or to the upper surface of stuffing giving skin puncture like sensation for the placebo needle; and (2) wherein the upper surface of the second stuffing or of the stuffing giving skin puncture like sensation is placed higher than the bottom end of the guide tube by an amount equal to the insertion depth of the safety needle, and the safety needle and the placebo needle can not be distinguished from their appearances.
 23. A needle set for double-blind test according to claim 21, wherein: the safety needle and the placebo needle are the same in their guide tube length, or in the distance from the end of the guide tube to be in contact with the skin to the end of the needle body holding stopper means to be in contact with the needle handle, in the length of the portion protruding from the top end of the guide tube or from the end of the needle body holding stopper means to be in contact with the needle handle, and in the length of their needle handles; and the safety needle and the placebo needle can not be distinguished from their appearances.
 24. A needle set for double-blind test according to claim 21, comprising: (1) a plurality of the safety needles, the safety needles being different from one another in one or more of the following features: the material, length, color and shape of a needle handle; the material, total length and diameter of a needle body; the length of the needle body protruding from the top end of a guide tube or from the needle body holding stopper means; the distance from the point of the needle body to the skin surface; the insertion depth; the material, length, color and shape of the guide tube; and the material, quantity, number and fixation position of a stuffing holding needle body, and (2) a plurality of the placebo needles, the placebo needles being different from one another in one or more of the following features: the material, length, color and shape of the needle handle; the material, total length and diameter of a needle body; the length of the needle body protruding from the top end of the guide tube or from the needle body holding stopper means; the distance from the point of the needle body to the upper surface of a second stuffing or of a stuffing giving skin puncture like sensation; the material, length, color and shape of the guide tube; the material, quantity, number and fixation position of the first stuffing, and the material, quantity, number and fixation position of the second stuffing or of stuffing giving skin puncture like sensation.
 25. A needle set for double-blind test according to claim 24, wherein the safety needles are different from each other only in diameter of the needle body, the placebo needles are different from each other only in diameter of the needle body, and the safety needles and the placebo needles are combined, thereby masking the diameters of the needle bodies.
 26. A needle set for double-blind test according to claim 24, wherein the safety needles are different from each other only in depth of the needle body insertion, the placebo needles are different from each other only in depth of the needle body insertion, and the safety needles and the placebo needles are combined, thereby masking the depths of the needle body insertions.
 27. A needle set for double-blind test according to claim 14, (1) wherein the safety needle and the placebo needle are the same in their guide tube lengths, or in the distance from the end of the guide tube to be in contact with the skin to the end of the needle body holding stopper means to be in contact with the needle handles, and in the length of their handle, and in the distance from the point of the needle body to the skin surface for the safety needle is the same as the distance from the point of the needle body to the upper surface of the second stuffing or to the upper surface of stuffing giving skin puncture like sensation for the placebo needle; and (2) wherein the upper surface of the second stuffing or of the stuffing giving skin puncture like sensation is placed higher than the bottom end of the guide tube by an amount equal to the insertion depth of the safety needle, and the safety needle and the placebo needle can not be distinguished from their appearances.
 28. A needle set for double-blind test according to claim 14, comprising: (1) a plurality of the safety needles, the safety needles being different from one another in one or more of the following features: the material, length, color and shape of a needle handle; the material, total length and diameter of a needle body; the length of the needle body protruding from the top end of a guide tube or from the needle body holding stopper means; the distance from the point of the needle body to the skin surface; the insertion depth; the material, length, color and shape of the guide tube; and the material, quantity, number and fixation position of a stuffing holding needle body, and (2) a plurality of the placebo needles, the placebo needles being different from one another in one or more of the following features: the material, length, color and shape of the needle handle; the material, total length and diameter of a needle body; the length of the needle body protruding from the top end of the guide tube or from the needle body holding stopper means; the distance from the point of the needle body to the upper surface of a second stuffing or of a stuffing giving skin puncture like sensation; the material, length, color and shape of the guide tube; the material, quantity, number and fixation position of the first stuffing, and the material, quantity, number and fixation position of the second stuffing or of stuffing giving skin puncture like sensation.
 29. A needle set for double-blind test according to claim 28, wherein the safety needles are different from each other only in diameter of the needle body, the placebo needles are different from each other only in diameter of the needle body, and the safety needles and the placebo needles are combined, thereby masking the diameters of the needle bodies.
 30. A needle set for double-blind test according to claim 28, wherein the safety needles are different from each other only in depth of the needle body insertion, the placebo needles are different from each other only in depth of the needle body insertion, and the safety needles and the placebo needles are combined, thereby masking the depths of the needle body insertions.
 31. A needle set for double-blind test comprising: (A) a safety needle according to one of a first construction and a second construction wherein: the first construction comprises: (1) a guide tube; (2) one or more stuffings holding needle body which are plugged into the guide tube to be fixed at a desired position, to give resistance to a needle body during its passage therethrough, and to hold the needle body; (3) the needle body movably held by the stuffing which has the length longer than that of the guide tube by an amount equal to the insertion depth of the needle body; and (4) a stopper which is mounted to the lower end of a needle handle attached to the top of the needle body, or which is mounted to the top end of the guide tube, and prevents the needle handle from advancing further at the moment when the needle point reach a specified insertion depth; (5) wherein the guide tube is longer than the insertion depth of the needle body; and the second construction comprises: (1) a guide tube; (2) a needle body holding stopper means which is mounted outside the top end of the guide tube, and which prevents a needle handle from advancing further into the guide tube when the point of the needle body reaches a specified insertion depth, and not only holds the needle body but gives resistance to it during its passage therethrough; and (3) the needle body movably held by the needle body holding stopper means which has the length longer than the distance from the end of the guide tube in contact with the skin to the end of the needle body holding stopper means to be in contact with the needle handle by an amount equal to the insertion depth of the needle body, (4) wherein the distance from the end of the needle body holding stopper means to be in contact with the needle handle from the end of the guide tube to be in contact with the skin is larger than the insertion depth of the needle body; and (B) a placebo needle comprising (1) a guide tube; (2) a needle body holding stopper means which is mounted outside the top end of the guide tube, and which prevents the needle handle from advancing further into the guide tube when the point of the needle body reaches just on or above the skin surface, and not only holds the needle body but gives resistance to it during its passage therethrough; (3) one or more stuffings giving skin puncture like sensation which are plugged into the guide tube to be fixed at a lower position, to give sensations indicative to the skin puncture and the tissue penetration during passage of a needle body through the cavity of the guide tube to reach the specified depth; and (4) the needle body movably held by the needle body holding stopper means which has the length sufficiently long to allow its point to stop just on or above the skin surface when the needle body is advanced through the cavity of the guide tube as far as possible.
 32. A needle set for double-blind test according to claim 31 wherein the point of the placebo needle body takes a form impenetrable to a human body.
 33. A needle set for double blind test according to claim 31 wherein the placebo needle guide tube has an adhesive or sucking pedestal on the surface of its base to be in contact with the skin.
 34. A needle set for double-blind test according to claim 31, (1) wherein the safety needle and the placebo needle are the same in their guide tube lengths, or in the distance from the end of the guide tube to be in contact with the skin to the end of the needle body holding stopper means to be in contact with the needle handles, and in the length of their handle, and in the distance from the point of the needle body to the skin surface for the safety needle is the same as the distance from the point of the needle body to the upper surface of the second stuffing or to the upper surface of stuffing giving skin puncture like sensation for the placebo needle; and (2) wherein the upper surface of the second stuffing or of the stuffing giving skin puncture like sensation is placed higher than the bottom end of the guide tube by an amount equal to the insertion depth of the safety needle, and the safety needle and the placebo needle can not be distinguished from their appearances.
 35. A needle set for double-blind test according to claim 31, comprising: (1) a plurality of the safety needles, the safety needles being different from one another in one or more of the following features: the material, length, color and shape of a needle handle; the material, total length and diameter of a needle body; the length of the needle body protruding from the top end of a guide tube or from the needle body holding stopper means; the distance from the point of the needle body to the skin surface; the insertion depth; the material, length, color and shape of the guide tube; and the material, quantity, number and fixation position of a stuffing holding needle body, and (2) a plurality of the placebo needles, the placebo needles being different from one another in one or more of the following features: the material, length, color and shape of the needle handle; the material, total length and diameter of a needle body; the length of the needle body protruding from the top end of the guide tube or from the needle body holding stopper means; the distance from the point of the needle body to the upper surface of a second stuffing or of a stuffing giving skin puncture like sensation; the material, length, color and shape of the guide tube; the material, quantity, number and fixation position of the first stuffing, and the material, quantity, number and fixation position of the second stuffing or of stuffing giving skin puncture like sensation.
 36. A needle set for double-blind test according to claim 35, wherein the safety needles are different from each other only in diameter of the needle body, the placebo needles are different from each other only in diameter of the needle body, and the safety needles and the placebo needles are combined, thereby masking the diameters of the needle bodies.
 37. A needle set for double-blind test according to claim 35, wherein the safety needles are different from each other only in depth of the needle body insertion, the placebo needles are different from each other only in depth of the needle body insertion, and the safety needles and the placebo needles are combined, thereby masking the depths of the needle body insertions.
 38. A needle set for double-blind test comprising: (A) a safety needle according to one of a first construction and a second construction wherein: the first construction comprises: (1) a guide tube; (2) one or more stuffings holding needle body which are plugged into the guide tube to be fixed at a desired position, to give resistance to a needle body during its passage therethrough, and to hold the needle body; (3) the needle body movably held by the stuffing which has the length longer than that of the guide tube by an amount equal to the insertion depth of the needle body; and (4) a stopper which is mounted to the lower end of a needle handle attached to the top of the needle body, or which is mounted to the top end of the guide tube, and prevents the needle handle from advancing further at the moment when the needle point reach a specified insertion depth; (5) wherein the guide tube is longer than the insertion depth of the needle body; and the second construction comprises: (1) a guide tube; (2) a needle body holding stopper means which is mounted outside the top end of the guide tube, and which prevents a needle handle from advancing further into the guide tube when the point of the needle body reaches a specified insertion depth, and not only holds the needle body but gives resistance to it during its passage therethrough; and (3) the needle body movably held by the needle body holding stopper means which has the length longer than the distance from the end of the guide tube in contact with the skin to the end of the needle body holding stopper means to be in contact with the needle handle by an amount equal to the insertion depth of the needle body, (4) wherein the distance from the end of the needle body holding stopper means to be in contact with the needle handle from the end of the guide tube to be in contact with the skin is larger than the insertion depth of the needle body; and (B) a placebo needle comprising (1) a guide tube; (2) one or more stuffings holding needle body which are plugged into the guide tube to be fixed at a desired position, to give resistance to the needle body during its passage therethrough; (3) the needle body movably held by the stuffing holding needle body which has the length sufficiently long to allow its point to stop just on or above the skin surface when the needle body being advanced through the cavity of the guide tube as far as possible; and (4) a stopper which is mounted to the lower end of a needle handle attached to the top of the needle body, or which is mounted to the top end of the guide tube, and prevents the needle handle from advancing further into the guide tube when the point of the needle body being advanced through the cavity of the guide tube reaches just on or above the skin.
 39. A needle set for double-blind test according to claim 38 wherein the point of the placebo needle body takes a form impenetrable to a human body.
 40. A needle set for double blind test according to claim 38 wherein the placebo needle guide tube has an adhesive or sucking pedestal on the surface of its base to be in contact with the skin.
 41. A needle set for double-blind test according to claim 38, wherein: the safety needle and the placebo needle are the same in their guide tube length, or in the distance from the end of the guide tube to be in contact with the skin to the end of the needle body holding stopper means to be in contact with the needle handle, in the length of the portion protruding from the top end of the guide tube or from the end of the needle body holding stopper means to be in contact with the needle handle, and in the length of their needle handles; and the safety needle and the placebo needle can not be distinguished from their appearances.
 42. A needle set for double-blind test comprising: (A) a safety needle according to one of a first construction and a second construction wherein: the first construction comprises: (1) a guide tube; (2) one or more stuffings holding needle body which are plugged into the guide tube to be fixed at a desired position, to give resistance to a needle body during its passage therethrough, and to hold the needle body; (3) the needle body movably held by the stuffing which has the length longer than that of the guide tube by an amount equal to the insertion depth of the needle body; and (4) a stopper which is mounted to the lower end of a needle handle attached to the top of the needle body, or which is mounted to the top end of the guide tube, and prevents the needle handle from advancing further at the moment when the needle point reach a specified insertion depth; (5) wherein the guide tube is longer than the insertion depth of the needle body; and the second construction comprises: (1) a guide tube; (2) a needle body holding stopper means which is mounted outside the top end of the guide tube, and which prevents a needle handle from advancing further into the guide tube when the point of the needle body reaches a specified insertion depth, and not only holds the needle body but gives resistance to it during its passage therethrough; and (3) the needle body movably held by the needle body holding stopper means which has the length longer than the distance from the end of the guide tube in contact with the skin to the end of the needle body holding stopper means to be in contact with the needle handle by an amount equal to the insertion depth of the needle body, (4) wherein the distance from the end of the needle body holding stopper means to be in contact with the needle handle from the end of the guide tube to be in contact with the skin is larger than the insertion depth of the needle body; and (B) a placebo needle comprising (1) a guide tube; (2) a needle body holding means which is mounted outside the top end of to the guide,and which prevents a needle handle from advancing further into the guide tube when the point of the body reaches just on or above the skin surface, and not only holds the body but gives resistance to it during its passage therethrough; and (3) the needle body movably held by thee needle body holding stopper means which has the length sufficiently long to allow its point to stop just on or above the skin surface when the needle body is advanced through the cavity of the guide tube as far as possible.
 43. A needle set for double-blind test according to claim 42 wherein the point of the placebo needle body takes a form impenetrable to a human body.
 44. A needle set for double blind test according to claim 42 wherein the placebo needle guide tube has an adhesive or sucking pedestal on the surface of its base to be in contact with the skin.
 45. A needle set for double-blind test according to claim 42, wherein the safety needle and the placebo needle are the same in their guide tube length, or in the distance from the end of the guide tube to be in contact with the skin to the end of the needle body holding stopper means to be in contact with the needle handle, in the length of the portion protruding from the top end of the guide tube or from the end of the needle body holding stopper means to be in contact with the needle handle, and in the length of their needle handles; and the safety needle and the placebo needle can not be distinguished from their appearances.
 46. A needle set for double-blind test according to claim 42, comprising: (1) a plurality of the safety needles, the safety needles being different from one another in one or more of the following features: the material, length, color and shape of a needle handle; the material, total length and diameter of a needle body; the length of the needle body protruding from the top end of a guide tube or from the needle body holding stopper means; the distance from the point of the needle body to the skin surface; the insertion depth; the material, length, color and shape of the guide tube; and the material, quantity, number and fixation position of a stuffing holding needle body, and (2) a plurality of the placebo needles, the placebo needles being different from one another in one or more of the following features: the material, length, color and shape of the needle handle; the material, total length and diameter of a needle body; the length of the needle body protruding from the top end of the guide tube or from the needle body holding stopper means; the distance from the point of the needle body to the upper surface of a second stuffing or of a stuffing giving skin puncture like sensation; the material, length, color and shape of the guide tube; the material, quantity, number and fixation position of the first stuffing, and the material, quantity, number and fixation position of the second stuffing or of stuffing giving skin puncture like sensation.
 47. A needle set for double-blind test according to claim 46, wherein the safety needles are different from each other only in diameter of the needle body, the placebo needles are different from each other only in diameter of the needle body, and the safety needles and the placebo needles are combined, thereby masking the diameters of the needle bodies.
 48. A needle set for double-blind test according to claim 46, wherein the safety needles are different from each other only in depth of the needle body insertion, the placebo needles are different from each other only in depth of the needle body insertion, and the safety needles and the placebo needles are combined, thereby masking the depths of the needle body insertions.
 49. A needle set for double-blind test according to claim 42, comprising: (1) a plurality of the safety needles, the safety needles being different from one another in one or more of the following features: the material, length, color and shape of a needle handle; the material, total length and diameter of a needle body; the length of the needle body protruding from the top end of a guide tube or from the needle body holding stopper means; the distance from the point of the needle body to the skin surface; the insertion depth; the material, length, color and shape of the guide tube; and the material, quantity, number and fixation position of a stuffing holding needle body, and (2) a plurality of the placebo needles, the placebo needles being different from one another in one or more of the following features: the material, length, color and shape of the needle handle; the material, total length and diameter of a needle body; the length of the needle body protruding from the top end of the guide tube or from the needle body holding stopper means; the distance from the point of the needle body to the upper surface of a second stuffing or of a stuffing giving skin puncture like sensation; the material, length, color and shape of the guide tube; the material, quantity, number and fixation position of the first stuffing, and the material, quantity, number and fixation position of the second stuffing or of stuffing giving skin puncture like sensation.
 50. A needle set for double-blind test according to claim 49, wherein the safety needles are different from each other only in diameter of the needle body, the placebo needles are different from each other only in diameter of the needle body, and the safety needles and the placebo needles are combined, thereby masking the diameters of the needle bodies.
 51. A needle set for double-blind test according to claim 49, wherein the safety needles are different from each other only in depth of the needle body insertion, the placebo needles are different from each other only in depth of the needle body insertion, and the safety needles and the placebo needles are combined, thereby masking the depths of the needle body insertions.
 52. A needle set for double-blind test according to claim 49, wherein the safety needles are different from each other only in depth of the needle body insertion, the placebo needles are different from each other only in depth of the needle body insertion, and the safety needles and the placebo needles are combined, thereby masking the depths of the needle body insertions. 